// 提供各种混合样式

@mixin self-center($pos: absolute) {
    position: $pos;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

@mixin self-fill($pos: absolute) {
    position: $pos;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

@mixin them($primary) {
    background: $primary;
}

